Importance

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Abstract

This invention relates to a reduced magnification, thinner lens structure, and improved vision for an aphakic patient by biconvexing the lens with the occular side of the lens having a correction of +0.25 to +6.00 diopters, and offsetting the tunnel vision effect by a high degree of asphericity and thinning of the lens outside of the central zone on the front of the lens. The lenses are nominally manufactured from four standard blanks of +8 diopters for use with prescriptions between +8.5 and +10.75; a +10 diopter blank for use with prescriptions of +11 through +12.75 diopters correction; a +12 diopter central blank for prescriptions of +13 through +14.75 diopters correction; and a +14 diopter central blank for use with corrections of +14.75 through +20. In each instance the balance of the correction is applied by convexing the ocular surface +0.25 to +6.00 diopters. The asphericity at 60 millimeters on the front base curve of +8.00 is -3 diopters; for a +10 front base curve -5.5 diopters; for a +12 base curve -8 diopters; and for a +14 base curve -9 diopters. The respective values at 53 millimeters which may be an average size lens are for the foregoing sequence -2.25; -4.25; -5.25; and -7. A 32 mm round seg for bifocal correction may be precast into the lens blank close to the central zone. It is a base down prism and thus forces the image towards the apex. The correction varies +2 to +5 in 0.25 diopter steps.

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First Claim